At Villefranche, walk to station along front, lot of steps up to station, ticket office on Monaco side, ticket 4.60 euros return, Monaco station quite large, take escalator DOWN from platform, tunnel walkway to port side. Oceanarium on top of hill by palace, would liked to have gone there but too hot for us. A "noddy" train ride is available round the streets from there for 6 euros, looked as though it gave a good overview. Other place we visited is superb--Jardin exotique at top of hill, back up tunnel to lift (elevator) to get up there. 600 varieties of cacti & superb views, entrance includes access to some caves 40 mins timed walk down & up 300 steps & also to anthropological museum on way out. enjoy but if you are walking the streets watch out for the doggie deposits all over the pavements, the chic ladies of monaco never clean it up as they walk their dear little pets, obviously the powers that be never walk the side walks so do not worry about any mad tourist who might find his way up the hill !!!.
Eric